The news about the slaughter of giraffe Marius is one of the most horrendous things I've ever read online. Already several petitions are circulating calling for the removal of Bengt Holst, the Director of Copenhagen Zoo. The problem here is that there is no fault with the Director: he was following the official procedures of the European Association of Zoos and Aquaria (EAZA). Check out their official commentary following Marius’ euthanasia: http://www.eaza.net/News/newsblog/Lists/Posts/Post.aspx?ID=183
That means that this can happen – and, statistically speaking, will happen again at some stage – at any European zoo. The fault is with EAZA official policy: that is what to be changed if we do not want Marius’ story to be repeated with some other animal in Dublin, Madrid, Moscow or anywhere else in Europe. To be precise, the point 4 of Euthanasia Considerations of the EAZA’s Euthanasia Statement of the 26/09/11 is to be removed:
http://www.eaza.net/about/Documents/EAZA%20Euthanasia%20statement.pdf